POLYPLOIDY INDUCTION OF DENDROBIUM FORMOSUM BY COLCHICINE TREATMENT IN VITRO
In vitro polyploidy induction using protocorm-like bodies (PLBs) of Dendrobium formosum was studied. PLBs were treated with colchicine at different concentrations at 0, 0.05, 0.10, 0.15 and 0.20% in liquid MS medium for 24 or 48 h. The PLBs were then transferred to basal MS medium solidified with 0.2% phytagel and subcultured at six weeks interval for six months. The results revealed that colchicine at concentration of 0.2% for 48 h gave the highest percentage of tetraploid plantlets. Morphological and physiological characters of those putative tetraploid plants were clearly different with the diploid plants. Tetraploid plants had thick and dark green leaves and large stem size. The stomata size, both length and width, of tetraploid plants were significantly larger than those of diploid plants, while their density was lower. Chromosome observation revealed that tetraploid plants had chromosome number 2n=4x=76 whereas diploid plants had 2n=2x=38. This evidence was also confirmed by flow cytometry.
Yenchon, S. and Te-chato, S. (2014). POLYPLOIDY INDUCTION OF DENDROBIUM FORMOSUM BY COLCHICINE TREATMENT IN VITRO. Acta Hortic. 1025, 81-88
tetraploid plants, flow cytometry, protocorm-like bodies, MS medium, phytagel